As various electric/electronic products are scaled down, research has been actively conducted to mount an increased number of chips to a substrate within a limited size and thereby realize miniaturization and high capacity. Accordingly, the size and thickness of a semiconductor package gradually decrease. For example, a chip size package, in which a chip size is no less than 80% of the total size of a semiconductor package, has been suggested. The chip size package has been developed into various types due to advantages resulting from a light, slim, compact and miniature structure thereof.
As a method of mounting typical semiconductor chips and some chip size packages to printed circuit boards, soldering using a lead frame is employed. While soldering using a lead frame may enhance performance in terms of a process and reliability, issues may be caused in terms of electrical characteristics due to the fact that a transfer length of an electrical signal is long. Under these situations, a flip chip package structure using bumps may minimize the electrical signal transfer length.
A flip chip package has a structure in which a semiconductor chip is bonded to a printed circuit board by bumps formed on bonding pads of the semiconductor chip and at the same time, the semiconductor chip and the printed circuit board are electrically connected with each other. In the flip chip package, since transfer of an electrical signal between the semiconductor chip and the printed circuit board is implemented only by the bumps, a signal transfer length becomes very short. However, if even one of the bumps connecting the semiconductor chip and the printed circuit board is poorly connected, a corresponding product cannot be used, which causes a decrease in manufacturing yield.
A method has been proposed, in which redistribution lines connected with bonding pads are formed on a semiconductor chip and at least two separate bumps are formed on the redistribution lines. While this method may lead to better manufacturing yield, since the redistribution lines and the bumps should be individually formed using separate masks, the manufacturing costs and the number of processes increase due to separate formation of the masks.